Hydraulic-valve mechanism



Aug. 6, 1929. LEROY w. SHUTTS HYDRAULIC VALVE MECHANISM Filed March 28,1927 Patented Aug. 6, 1929.

UNITED STATES PATENT OFFICE.

LEROY. W. SHUTTS, OF DETROIT, MICHIGAN, ASSIGNOR TO GENERAL MOTORS RE-SEARCH CORPORATION, OF DETROIT, MICHIGAN, A CORPORATION OF DELAWARE.

HYDRAULIC-VALVE MECHANISM.

Application led March 28, 1927. Serial No. 179,002.

This invention relates to an hydraulic valve gear of the type in which abody of oil is 1nterposed between operating plunger-s, one .of which isactuated by the cam shaft or equivalent mechanism and the other of whichis arranged t0` operate,I the engine valve. It has particularly to dowith an inlet valve arranged to permit the entrance of oil to maintainthe hydraulic chamber filled and, at

the same time, permit the escape of air which may collect in the upperportion of the hydraulie chamber. The valve gear is of the typedisclosed and claimed in the prior application of George E. A. Hallett,Serial No.

126,297, tiled July 31st, 1926, although it embodies certain novelfeatures hereinafter claimed.

In the drawings, Figure 1 is a vertical section thru suoli an hydraulicvalve gear as applied to an overhead valve engine. Figure 2 is a detailof the valve mechanism with the parts in a slightly different position.

The reference character 2 indicates a portion of a conventionalautomobile engine of the type employing overhead valves,

although it is to be understood that my invention is equally useful withL-head or V-type engines.

Reference character 4 indicates the stem of one of the usual poppetvalves yieldingly held upon its seat by coil spring 5. 6 indicates apush rod operated by the usual cam shaft, not shown. 8 indicates anhydrallllc chamber in which operate pistons 10 and 12. Piston l()engages the upper end of the valve stem 4 while piston 12 engages theupper. end of the push rod 6. A light spring 14 yieldingly urges thepiston 12 downwardly and a similar spring may be provided for the piston10. Above the hydraulic chamber 8 is arrangedv a reservoir 16 suppliedwith oil from any suitable source, such as the usual oil pump, thruconduit 18. The reservoir 16 is provided with a pressure relief. valve20 permitting the return of oil through conduit 22 to the crankcase. At24, I have indicated my improved valve. This valve is arranged at-thehighest point in the chamber 8 and consists of fitting 26 receivingscrew plug 28 which, in turn, receives screw 'pluo 30. The plug 28 isprovided at its lower end with an axial bore 32 and at its intermediateportion with a bore 34 somewhat larger in diameter than the reduced end36 of plug 30, but smaller in diameter than bore 32 forming a seat orshoulder 48. Radial passages 35 establish communication between bore 34and chamber 16. The plug 30 is provided with an axial bore 38 from whichsmall passages .40 lead to the lower face ofthe plug 30, at pointsspaced from the axis. lVithin the bore 32 is arranged a valve 44 of thinmetal vieldingly urged upwardly by coil spring 46. This spring normallyholds the valve 44 in engagement with the shoulder 48 provided at thejunction of the bores 32 and 34. The reduced end 36 of plug 30terminates short of the disc 44 in its normal position. Disc 44 isprovided with a small central aperture 50.

The device operates as follows:

In normal operation, the push rod 6 is reciprocated by the cam shaft andeffects reciprocating movement of plunger 12 which is conveyed toplunger 10 through the oil in the reservoir 8. By this mea-ns, the valve4 is alternately opened and closed. Reservoir 16 is at all times full ofoil under pressure and upon the return stroke of `t-he piston 12 shouldthe chamber 8 notbe full of oil, oil will pass from the reservoir 16through passage 35 and bore 34, depress valve 44 and pass around thevalve through bore 32 into the chamber 8. Any air which may collect inthe upperpart of chamber 8 will tend to pass upwardly throughaperture'50, passages 40 and bore 38 into the upper portion of thechamber 16 and thence be carried off through relief valve 2() andreturned to the crankcase. The described discharge of air can take placeeven though the pressure in the chamber 8 be sufficiently great to holddisc 44 in engagement Ywith shoulder 48 and consequently shut offpassage of oil around the valve. However, it is undesirable to have thevalve 44- open during the operating stroke of the plunger 12 even to theextent of having the restricted passage 50 uncovered. This is` takencare of by the fact that the valve 44 is of very flexible material andwhensubjected tothe full operating pressure in the chamber 8, is flexedupwardly sealing the aperture 50 by engagement with the lower end ofplug 30.

lhile l have shown my improved valve used as both inlet and outletvalve, it is obvious that it may be used as an outlet valve only as inthe Hallett application referred to.

I claim: p

l. The combination of an hydraulic chamber, an operating member and anoperated member Working in the chamber, a luid reservoir and a valveestablishing communication between the reservoir and chamber, said valvecomprising a main passage for the admission of the fluid to the chamberand an auxiliary passage of smaller size for the venting of air. 'l

2. The combination of an hydraulic chamber, an operating member and an`operated member Working in the chamber, a source of fluid supply, and avalve interposed between said source and the chamber, said valve beingprovided With a main passage for the admission of fluid tothe chamberand an auxiliary passage for'the venting of air, and a valve memberadapted to close one or both of said passages dependent upon thepressure in the chamber.

3. The combination of a hydraulic chamber, an operating member andanoperated member Working in the chamber, a body of Huid in the chamberfor transmitting motion from the operating memberto the operated member, a combined iiuid inlet and air vent valve arranged at the highestpoint in the chamber, and a reservoir containing tluid under pressurewith which said valve establishes communication.

4, The combination ot a hydraulic cham ber, an operating member and anoperated voir provided with a plurality of passages,\

valve seats associated with each of said passages, a valve membercooperating with said seats, means for normally urging the valve memberinto engagement With one of said seats in opposition to the pressure insaid reservoir, said valve member being operable to engage the secondnamed seat when subject to the operating pressure of the hydraulicchamber.

5. The combination of a hydraulic chamber, an operating member and anoperated member Working in the chamber, a body ot fluid in the chamberfor transmitting motion from the operating member to the operatedmember, a reservoir containing fluid under pressure, and a valve forestablishing communication between said chamber and reservoir providedwith a plurality of passages, valve seats associated with each ofsaidpassages, a disc, a spring for urging the disc into engagement With oneof the seats in opposition to the pressure in said reservoir, said discbeing distortable to engage the second named seat when subjectto theoperating pressure of the hydraulic chamber.

ln testimony whereof l aix my signature.

LERGY W.. SHUTTS.

